Insect repellent



Patented Sept. 11, 1951 UNITED STATES TENT QFFICE INSECT REPELLENT No Drawing. Application January 10, 1949, Serial Ne. 70,138

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 3 Claims.

The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to insect repellents.

I have found that the application of the dimethyl ether of pyrogallol, a compound having the structural formula HO.C6H3.(OCH3)2, to the human skin .or to afabric affords effective protection against insect bites, by repelling insects, particularly the Aedes aegypti and the Anopheles quadrz'maculatus.

A number of tests to measure the repellency of the dimethyl ether of pyrogallol against Aedes aegypti was conducted by smearing the com pound on the arms of test personnel, who then thrust their arms into cages containing Aedes aegypti. The arms were exposed for 30-minute intervals at 3 minutes each until the first insect bite.

Tests to measure the repellency of the dimethyl ether of pyrogallol impregnated fabrics against Aedes aegypti were conducted by uniforml impregnating mercerized cotton hose with the compound at a rate equivalent to 3.3 gms. per sq. ft., drawing the dried hose over the arms of test personnel, who then thrust their covered arms into cages containin Aedes aegypti for l to 2 minutes. If no bites or less than 5 bites were received, the tests were repeated each successive K day until 5 or more bites during one exposure were received.

It was found that the application of the dimethyl ether of pyrogallol affords protection against Aedes aegypti for an average of 234 minutes. Against Anopheles quadrimaculatus, an average repellency time of 52 minutes was noted in analogous tests.

It was found that fabric impregnated with the dimethyl ether of pyrogallol remained repellent to Aedes aegypti for over 5 successive days.

For ease of application to the skin, the dimethyl ether of pyrogallol may be incorporated in a suitable inert liquid or solid carrier such as mineral oil, alcohol, petrolatum, etc. For ease and uniiormity of application to the fabric, the dimethyl ether of pyrogallo] may be applied to the fabric in an inert solvent, such as alcohol, ether, etc.

Having thus describec my invention, I claim:

1. An insect-repellent fabric comprising fabric impregnated with the dimethyl ether of pyrogallol.

2. A process of repelling insects, comprising applying the dimethyl ether of pyrogallol to the region from which the insects are to be repelled.

3. A process of repelling insects, comprising applying the dimethyl ether of pyrogallol to the skin.

MARSHALL GATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Jones et a1. May '7, 1946 OTHER REFERENCES Number 

1. AN INSECT-REPELLENT FABRIC COMPRISING FABRIC IMPREGNATED WITH THE DIMETHYL ETHER OF PYROGALLOL. 